Lubrication of the moving components of an internal combustion engine is often important in the proper operation of the engine. Conventional internal combustion engines have several systems and sub-systems requiring lubrication for proper operation. For example, some conventional internal combustion engines include gear trains, fuel pumps, lubrication pumps, air compressors, valve systems, camshaft systems, and/or other components and systems that may utilize lubrication to reduce friction and parasitic losses during operation.
Many conventional internal combustion engines include a lubrication supply system with a source, such as an oil pan, and a pump. During operation of the internal combustion engine, the pump pressurizes lubrication from the lubricant source while supplying the pressurized lubrication to the various lubricated systems and sub-systems of the engine. Some lubrication systems, such as gear trains, receive pressured oil to lubricate the systems, while concurrently draining used lubrication from the systems back to the lubricant source to prevent undesirable amounts of lubrication from pooling within the systems. In certain systems, the pooling of pressurized oil during operation may lead to inefficiencies, including the degradation and failure of seals. Accordingly, bleeding lubrication out of the systems during operation of the engine may be desirable. Certain conventional systems do not regulate or control the flow of lubrication from the systems. Following operation of the engine, lubrication is allowed to continuously drain from the systems back to the lubrication source such that no lubrication is left pooled in the systems.
Because lubrication is substantially completely drained from the lubricated systems after shutting down or following operation of the internal combustion engine, lubrication must be supplied to the systems upon start-up or initializing operation of the engine. However, lubrication is also drained from the lubrication supply system while the engine is shut down. Upon start-up of the engine, the lubrication supply lines of the lubrication supply system are populated with lubrication via the pumping action of the pump before lubrication can be supplied to the lubricated systems. Populating the lubrication supply lines following start-up of the engine, particularly following a cold-start of the engine when the lubrication is most viscous, can significantly delay the introduction of lubrication into the lubrication system. The delay in the lubrication supply to the lubricated systems results in periods of unlubricated operation of the lubricated systems, which may cause an increase in the friction and parasitic losses of the engine.